During the past twenty-five years, research efforts have enabled the elucidation of olefin metathesis reactions catalyzed by transition metal complexes. In particular, certain ruthenium and osmium carbene compounds have been identified as effective catalysts for olefin metathesis reactions such as, for example, ring opening metathesis polymerization (ROMP). Such metathesis catalysts have been previously described in, for example, U.S. Pat. Nos. 5,312,940; 5,342,909; 5,728,917; 5,710,298; and 5,831,108; PCT Publications WO 97/20865 and WO 97/29135; and in U.S. Provisional Patent Application No. 60/115,358, filed Jan. 8, 1999 by inventors Steven P. Nolan and Jinkun Huang entitled “Novel Metathesis Catalyst Compositions and Methods for Their Use,” the disclosures of which are incorporated herein by reference.
Examples of olefin monomers that may be polymerized using the aforementioned metathesis catalysts include dicyclopentadiene (DCPD), in addition to other strained cyclic olefin compounds. Polymer compositions, and articles or parts produced therefrom, are useful in a wide variety of applications because of their unique physical properties and ease of fabrication. In particular, poly-DCPD compositions show promise for applications requiring a combination of toughness, hardness, elasticity, rebounding qualities, marine anti-fouling and/or corrosion resistance, among other properties. In addition, the low viscosity of DCPD-based compositions makes these resins particularly well-suited to the fabrication of complex shapes and composites.
Numerous common polymer additives, including pigments, dyes, plasticizers, rubber particles and antioxidants, among others, have been included in polymer compositions in an effort to vary or preserve over time one or more physical properties of the polymer. However, these additives may also effect unintended or undesirable changes in one or more physical properties. Thus, it has not been possible using traditional high-viscosity thermoset resins to vary the hardness, toughness or surface “feel” of the resin compositions, or parts thereof, through the addition of these additives without compromising one or more desirable properties of the native polymer. In addition, the surface “feel” or texture, as well as the elasticity, toughness and hardness of a polymer composition, or parts made thereof, may be important considerations in certain commercial applications.
In light of the foregoing, there exists a need for polymer compositions, and articles of manufacture thereof, which may be formulated to have variable toughness and/or hardness for use in a wide range of commercial applications. This is especially so for materials related to the sports, recreational and marine industries. Preferably, the compositions' properties are not compromised by the incorporation of additives giving rise to the beneficial toughness and/or hardness characteristics.